1. Field of the Invention
The present invention relates generally to an apparatus and method for controlling a mobile communication terminal in a data communication system, and in particular, to an apparatus and method for controlling a mobile communication terminal that involves data communication as a modem.
2. Description of the Related Art
A data communication system using a mobile communication terminal, which will hereinafter be simply referred to as a mobile terminal, is an environment where a mobile terminal is used as a modem and a personal computer or a laptop computer that controls the mobile terminal builds up a Point-to-Point Protocol (PPP) connection in a dial-up modem method and gets access to a network. The mobile terminal displays information on data reception and transmission.
FIG. 1 illustrates a conventional data communication system using a mobile terminal. Referring to FIG. 1, the conventional data communication system is composed of a network terminal 100, a mobile terminal 110 that functions as a modem and provides a data communication service to network terminal 100, a Packet Data Serving Node (PDSN) 120, Internet 130, and a destination host 140. PDSN 120 is connected to the Internet and provides a wireless data communication service.
In the conventional data communication system, it is impossible to use an application program such as searching a telephone number database and reading a Short Message Service (SMS) message in mobile terminal 100 or network terminal 100, such as a personal computer (PC) and a laptop computer, while mobile terminal 110 operates as a modem and involves data communication. The reason will be described below based on the protocol structure of the data communication system.
FIG. 2 illustrates the communication protocol structure of a conventional data communication system using a mobile terminal. Referring to FIG. 2, network terminal 100 creates Transmission Control Procedure (TCP) packets or User Datagram Protocol (UDP) packets and transmits the packets to communicate data with destination host 140. Mobile terminal 110 does not check encapsulated packet data transmitted from network terminal 100 and it operates as a repeater for repeating them to PDSN 120. Since a corresponding port is in use during the data communication, network terminal 100 cannot transmit a predetermined control command to mobile terminal 110. Therefore, the network terminal 100 cannot control the mobile terminal 110 with its control command.
For this reason, it is required to develop an apparatus and method that makes it possible to use a database and such applications as SMS in mobile terminal 110 through network terminal 100 even if the data communication system is in the middle of data communication.